<template>
  <div class="app-container">
    <el-form label-width="120px">
      <el-form-item label="信息描述">
        <el-tag type="info">excel模版说明</el-tag>
        <el-tag>
          <i class="el-icon-download"/>
          <a :href="defaultExcelTemplate">点击下载模版</a>
        </el-tag>
      </el-form-item>
      <el-form-item label="选择Excel">
        <el-upload
          ref="upload"
          :auto-upload="false"
          :on-exceed="fileUploadExceed"
          :on-success="fileUploadSuccess"
          :on-error="fileUploadError"
          :limit="1"
          :action="BASE_API+'/admin/edu/subject/import'"
          name="file"
          accept="application/vnd.ms-excel">
          <el-button
            slot="trigger"
            size="small"
            type="primary">选取文件</el-button>
          <el-button
            :disabled="importBtnDisabled"
            style="margin-left: 10px;"
            size="small"
            type="success"
            @click="submitUpload()">导入</el-button>
        </el-upload>
      </el-form-item>
    </el-form>
  </div>
</template>
<script>
export default {
  data() {
    return {
      BASE_API: process.env.BASE_API,
      // 请求地址中如果包含中文，默认会采用URLEncode编码
      defaultExcelTemplate: process.env.OSS_PATH + '/excel/课程分类列表模板.xls', // 默认Excel模板
      flag: false// 导入按钮是否禁用
    }
  },
  methods: {
    // 上传多于一个文件时
    fileUploadExceed() {
      this.$message.warning('只能选取一个文件')
    },
    // 上传
    submitUpload() {
      this.flag = true
      this.$refs.upload.submit()// 提交上传请求
    },
    // 上传成功
    fileUploadSuccess(res) {
      if (res.success) {
        this.flag = false// 启用按钮
        this.$message.success(res.message)
        this.$refs.upload.clearFiles()// 清空文件列表
      } else {
        this.$message.error('上传失败!(非20000)')
      }
    },
    // 上传失败
    fileUploadError() {
      this.flag = false// 启用按钮
      this.$message.error('上传失败!(http失败)')
      this.$refs.upload.clearFiles()// 清空文件列表
    }
  }
}
</script>
